Fusion of separate hyobranchial elements into a hyobranchial (=hyoid) plate

A tongue that lacks intrinsic skeletal support from the hyobranchial plate

A tadpole, with keratinous beaks and denticles as larval mouthparts

A single median spiracle in the larva (characteristic of Orton's Type 3 tadpole)

Large subcutaneous lymph spaces between the skin and muscle layer

Two protractor lentis muscles attached to lens

(Milner, 1988, 1993; Saint-Aubain, 1981; Trueb and Cloutier, 1991).

However, the existence of several early frog fossils, such as †Prosalirus and †Notobatrachus, clouds this picture, because many of these characters cannot be assessed in these fossils, either because of incompleteness of fossils or because the features are soft-tissue characters identifiable only in living taxa.